Production of glass in strip form and apparatus therefor



PRODUCTION OF GLASS IN STRIP FORM AND APPARATUS THEREFOR Original Filed April 27, 1929 My, 1 W

Patented June 30, 1931 UNITED STATES PATENT OFFICE ERNEST BRISTOW LE MARE, OF ST. HELENS, ENGLAND, ASSIGNOR TO PILKINGTON BROTHERS LIMITED, OF LIVERPOOL'ENGLAND, A LIMITED LIABILITY COMPANY PRODUCTION OF GLASS IN STRIP FORM AND APPARATUS THEREFOR Original application filed. April 27, 1929, Serial No. 358,439, and in Great Britain May 1, 1928.

and this application filed May 21, 1930.

Applications have been filed in Great Brit ain, May 1, 1928; Belgium, April 26, 1929; Czechoslovakia, April 26, 1929; France, April 26, 1929; and Germany, April 26, 19295 This invention relates to the production of glass in strip form and has for its object an improved process and apparatus whereby lengths of strip may be formed intermittently and the strips passed through a lehr at a speed equal to the speed of formation averaged over the periods of formation and intermittence.

In the production of glass in strip form, it is frequently necessary to form the strip at high speed, say, 30 feet per minute. If the strip were passed through a lehr at this speed, the necessary length of lehr would be impracticable.

It has been proposed to form strips at the desired high speed, butintermittently, the average speed of formation, including the time of intermittence, being a speed, say, 3 feet per minute, which is suitable for a lehr of normal length, and certain devices have been proposed whereby the strip is received at the high speed and reduced in speed to the low speed.

According to this invention the strip is received at the high speed and reduced in speed in a way which is simpler, maintains better the flatness of the strip and by simpler devices.

In the accompanying drawings Figure 1 is a longitudinal section, partly broken away, of a lehr with roller bed for carrying out the invention;

Figure 2 is part horizontal section thereof on a larger scale showing the driving devices of the rollers, and

Figure 3 is a view similar to Figure 2 of an alternative form of the driving means.

Referring to Figure 1, the lehr 1 is provided with a bed of rollers 2. Some of the rollers 2 are driven by means to be herein-' after described, in a direction tending to retard the speed of the strip. The remaining rollers of the lehr, hereinafter called the ordinary rollers, are driven all at the same speed and in the same direction.

The shafts 3 of the rollers 2 turn in bear- Divided Serial No. 454,292.

ings 4; supported on a foundation wall 5 outside the lehr wall 6.

Alternate rollers 2 and 2 carry on their shafts 3, extending beyond the bearings 4, chain wheels 30 and 31 respectively. series of chain wheels 30 are driven by a chain 28 and the series 31 by a chain 29. The rollers 2 are driven at a constant speed while the rollers 2 are driven by.or through v K a reversible variable speed device. Then, by varying the speed and the direction of rotation of the rollers 2, the effective speed of the bed may be varied within any desired limits. Thus, the rollers 2 may be turned at a constant speed of 30 feet per minute; then, to receive the strip, the rollers 2 are also turned at this speed. At any suitable moment, the direction of rotation of the rollers 2 is reversed and their speed gradually increased so as gradually to diminish the efiective speed of the roller bed down to three feet per minute.

The strip then passes on to the ordinary rollers of the lehr which are driven at this speed.

Another device for varying the effective speed of the roller bed is shown in Figure 3, which is a view similar to Figure 2, showing one roller 32 only. he shaft 3 of this roller carries two chain wheels 33 and 34, which are engaged with two chains 35 and 36 respectively, travelling in opposite directions. T he two chain wheels 33 and 3 1 can turn freely on the shaft 3 and are provided with clutch members 37 and 38 respectively. A piece 39, adapted to slide on a feather on. the shaft 3 has clutch members 40 and ll adapted to engage respectively with the clutch members 37 and 38. adapted to turn the rollers so as to move the strip forward at the speed of, say, 30 feet per minute. The chain 36 is adapted to turn the rollers so as to move the strip backward at the speed of, say, 27 feet per minute. Every alternate roller is provided with the two chain wheels and clutches as in Figure 3, While the other rollers are permanently driven by the chains 35 as are the rollers of Figure 2. The operation of the device is then as follows :All the clutch members its The chain 35 is 40 are engaged with the clutch members 37 so that all the rollers are turned to move the strip forward at the speed of 30 feet per minute. The bed of rollers is then adapted to receive the strip. As soon as the whole strip is on the bed, the piece 39 on the shafts of certain of the rollers is moved over to engage the clutch members 38 and 4 1,

thereby causing these rollers to turn in the opposite direction at 27 feet per minute. For instance, every eighth roller may thus be reversed, whenthe effective speed of the bed wi l-be edu ed t about feet per min.-

nte; then every fourth rollermay be reversed, reducing it to 1.5 feet per minute and finally every second roller isreversed, reducing it to three feet per minute.

The rollersatthe entering end of the lehr, for a certain distance,:need not, any of them,

be provided with the reversingdevice shown in Figure 3, and the proportion of the rollers .so provided maybe increasedprogressively along the lehr until (finally every alternate roller is so provided.

In the ahove-described devices, the rate. at which the speed of the strip is retarded is so related to the interval between the formation of successive strips that, on the ordinary rollers of the lehr, the strips follow one another closely.

The means for drivingathe rollers, by chains is shown by way of example only; they may be driven, by any suitable devices, such as bevel or spiral gears.

Hav ng described my invention, I declare th t What Iclaim and desire to, secure-by Let.-

by turnin some of the rollers supporting the strip constantly in a forward direction and others intermittently in a backward direct on. 7

, 4, Process of gradually reducing the speed of a hot glassstrip travelling on a roller-bed by turning a certain number of the rollers supporting the strip constantly in a forward dire tion. and a'difiierent number of the rollers in a backward direction.

duced, at a constant speed, and means for driving the other rollers in the same portion independently, the latter means being adapted to reverse the direction of rotation of the rollers and to vary their speed, the two classes of rollers being so intermingled that the strip always rests on rollers of both classes.

n t ss wh re I ave -fixedmy si nature hereto.

ERNEST BRISTOl/V LE .MARE.

5., Roller-bed for intermittently receiving 7 hot glass strips at a high speed and reducing their speed, characterized by means for d-rivsome of the rollers, in the portion of the bedover which the speed of the strip'is reice 

